Iran said Monday that a general in its elite Revolutionary Guards who’d been sent to Syria to help that country battle rebels died in an Israeli air strike on Sunday, raising tensions and heightening expectations of possible retaliation.

A statement on the website of the Iranian Revolutionary Guards said that Gen. Mohammad Ali Allahdadi was killed when Israeli planes bombed a convoy in southern Syria, where troops loyal to President Bashar Assad have been fighting rebels that include al Qaida’s Nusra Front.

The statement said Allahdadi had been helping the Syrian government “confront the takfiri Salafist terrorists,” using religious terms to refer to the Sunni Muslim rebels who’ve been trying to topple Assad for nearly four years.

Also killed were five Iranians, according to the AFP news agency, and six members of Lebanon’s Hezbollah, including a prominent Hezbollah operative, Jihad Mughniyah, whose father, Imad Mughniyah, was the group’s military chief until he was assassinated in 2008.

As Israeli forces went on alert for a possible reprisal, Iranian and Hezbollah officials warned that a response would come “at the right time and place.”

Hezbollah and Iran, which both adhere to the Shiite branch of Islam, have sent fighters to help Assad’s forces counter the predominantly Sunni Muslim rebels. Iran has been Assad’s main regional ally in the conflict.

Al Manar, the Hezbollah television station, said that the group’s fighters were killed while inspecting positions at Mazraat Amal, a village near the frontier with the Israeli-held Golan Heights. Hezbollah has been assisting Syrian government forces in the area.

Analysts said that the Israeli strike, the first attack on Hezbollah operatives in Syria since the start of the civil war, was meant to signal that Israel would not tolerate Hezbollah activities along the Golan Heights frontier.